A 3-D image chamber for the liquid argon TPC based on multi-layer printed circuit board

In our research and development programme for the ICARUS experiment we have developed a novel three-dimensional readout scheme for a liquefied noble gas TPC, where no charge multiplication process takes place. The design avoids completely wire grids and is based on the multilayer circuit technique. As a consequence it is intrinsically safe and suited to be used in large and modular structures as those foreseen for ICARUS. We describe here how the electrodes structure can be simplified leading to the new design principles and we present the results obtained with a small prototype chamber in a 100 GeV μ beam.